The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Vehicle article carrier systems have been in widespread use for a number of years, and are presently growing in popularity, due in part to the growing popularity of SUVs and mini-vans, and the general interest in increasing the cargo carrying capability of passenger motor vehicles.
A typical vehicle article carrier includes a pair of support rails which are fixedly secured to the roof surface of the vehicle. Typically at least one cross bar is included which has an end support at each end. The end supports typically clamp onto the one of the support rails to provide a surface above the outer body surface that may be used to support articles or other implements (e.g., bike racks, ski racks, cargo boxes, etc.) thereon.
Typically, an end support has traditionally made use of a locking pin which can be engaged with an opening in its associated support rail to positively lock the end support at a specific location along the length of the support rail. This has traditionally been needed because per U.S. federal crash test requirements, the end supports, and the cross bar which they support from the support rails, must not be able to slide along the support rails for any appreciable distance during an impact event. Traditionally, the idea of just relying on the clamping force provided by the end support to provide sufficient force to prevent movement of the cross bar during a crash event has been dismissed because of the inability of heretofore designed end supports to consistently provide the high degree of clamping force required to meet such crash tests. This is further complicated by slight variations in the dimensions of the support rails, slight variations in the thicknesses of rubber or elastomer layer surfaces which are often applied to the clamping surfaces of the end support components, and other variables, which can affect how much clamping force the end support exerts on its support rail. For example, if a support rail has a slightly smaller than expected cross sectional dimension, then the clamping force provided by the end support will be just slightly reduced. The same can be said if the rubber/elastomer pads used on the clamping surfaces of the end support have a thickness which is less than specified.
Another important consideration is that the end support clamping mechanism must be easy for an individual to latch and unlatch without requiring any external tools. Simply designing the end support with an added degree of clamping force beyond what is needed to effect secure clamping may make it unduly difficult for an individual to manipulate the end support between its latched and unlatched conditions. So ideally, the precise degree of force required to effect the clamping needs to be determined, and the additional force beyond that amount needs to be carefully controlled so that user latching and unlatching of the end support can be comfortably carried out. Meeting these opposing requirements has heretofore not been possible without incorporating some form of locking pin into the end support design.